Early automobiles had front bumpers that were deeply resilient and extended well in front of the vehicle body. Such bumpers were adapted for pushing gates open. Later automobiles have had bumpers close to the body shell, which together with variations in bumper styles prevents opening conventional gates with direct vehicle thrust.
Electric motor driven gates that the driver can control from his cab are now available, but each vehicle must carry a controller, and electricity must be available or provided by a battery. In connection with electric fencing, electrified arms and other reduced structures can be used as push-through gates. Such gates are respected by livestock, are virtually unaffected by wind and yield readily to vehicles. However, electrified fences and gates can injure humans and are thus limited in their application.
Livestock also respects barbed wire. A distinction needs to be made between stockyard gates in which strength is the dominant consideration and gates for outfences and driveways, such as the present invention, where animals are not closely confined and escape when the gate is left standing open, rather than through structural failure of the gate.